Yes, Dear - Season 2 Episode 12 One Fish, Two Fish, Dead Fish, Blue Fish

At a school carnival, Kim persuades Greg to try to win a fish for Sam. Greg doesn't want a fish, so he tries to lose on purpose. But Jimmy comes along and wins it. Sam likes the fish so much that Kim gloats about how right she was. The next morning, though, the fish dies. Kim makes Greg have to explain to Sam what happened to it, so he butters him up with the promise of a new fish and some candy. Then Kim overrides Greg's explanation and tries to make Sam sad, which ticks off Greg. Since he believes she's making the situation worse and doesn't respect him, Greg starts argument #1 with Kim. Jimmy finds out about it and tells Greg that Christine is his puppet and he loses arguments with her on purpose just so they can get to the make-up sex faster. And since Greg never wins any arguments with Kim anyway, he should do the same. So Greg goes home and takes a dive, which Kim falls for. But Greg can't bear to play Jimmy's game for very long, and soon admits the truth. Which spurs argument #2